例句與造句

1. They form the only known infinite family ( with respect to having a constant ? value ) of symmetric block designs.
2. The set of all translates of a difference set "'D "'forms a symmetric block design.
3. The Fano plane is a small symmetric block design, specifically a 2-( 7, 3, 1 )-design.
4. It's difficult to find symmetric block design in a sentence. 用symmetric block design造句挺難的